Acryloyl-functionalized linear polydimethylsiloxanes can have a satisfactory oxygen permeability yet suffer from hydrophobicity, thereby repelling water and increasing the incidence of corneal staining. That is, introduction of a siloxanyl group for the purpose of increasing oxygen permeability can negatively impact other properties of the composition. Further, when an acryloyl-functionalized polydimethylsiloxane is copolymerized with a hydrophilic monomer (e.g., 2-hydroxyethyl(meth)acrylate) in order to increase the hydrophilicity, phase separation can occur due to the static repulsion between the polar hydroxyl group and the nonpolar siloxanyl group, so that a transparent polymer cannot be obtained. Accordingly, such compositions can have poor optical quality.
Therefore, there remains a need for methods and compositions that overcome these deficiencies and that effectively attain a satisfactory balance between oxygen permeability and hydrophilicity.